X-ray fluoroscopic imaging device

Abstract

An X-ray fluoroscopic imaging device (100) comprises a control unit (6) that performs control for causing irradiation of X-rays by an X-ray irradiation unit (21) on the basis of an input operation of an operation unit (3), and performs control for generating an X-ray image. The control unit (6) is configured such that when the pixel value of a pixel included in the generated X-ray image is included in the range of a target pixel value (58), the X-ray irradiation by the X-ray irradiation unit (21) is stopped even when reception of the input operation for causing irradiation of X-rays is continued by the operation unit (3).

Description

X-ray fluoroscopy equipment

[0001] The present invention relates to an X-ray fluoroscopic imaging apparatus.

[0002] BACKGROUND ART X-ray fluoroscopic imaging devices that perform fluoroscopic imaging of a subject using X-rays have been known. Such an X-ray imaging device is disclosed, for example, in International Publication No. 2018 / 025347.

[0003] WO 2018 / 025347 discloses that, in an X-ray fluoroscopy apparatus, when X-ray fluoroscopy of a subject is started, X-ray irradiation conditions are changed so that the luminance value (pixel value) of the X-ray image becomes an ideal luminance value (target pixel value) in order to display an X-ray image with appropriate luminance. This X-ray fluoroscopy apparatus automatically adjusts the X-ray irradiation conditions for X-ray images intermittently generated by X-ray fluoroscopy.

[0004] International Publication No. 2018 / 025347

[0005] Although not described in WO 2018 / 025347, a typical X-ray fluoroscopy device is equipped with, for example, an X-ray fluoroscopy foot switch. When the X-ray fluoroscopy foot switch is depressed, X-rays are emitted from the X-ray irradiation unit, thereby starting X-ray fluoroscopy. When the foot is released from the depressed X-ray fluoroscopy foot switch, X-ray irradiation from the X-ray irradiation unit is stopped, thereby ending X-ray fluoroscopy.

[0006] In the X-ray fluoroscopy apparatus of International Publication No. 2018 / 025347, if the time the X-ray fluoroscopy foot switch (operation unit) is pressed is shortened to reduce radiation exposure, the brightness values ​​(pixel values) of the X-ray image generated based on the changed X-ray irradiation conditions may not converge to the ideal brightness values ​​(target pixel values), which may result in an X-ray image with improved visibility. In contrast, if the time the X-ray fluoroscopy foot switch is pressed is lengthened to reliably obtain an X-ray image with improved visibility, the X-ray exposure time may increase, which may result in an increase in the subject's radiation exposure. Therefore, it is desirable to obtain X-ray images with improved visibility while suppressing an increase in the subject's radiation exposure.

[0007] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide an X-ray fluoroscopy apparatus that can obtain X-ray images with improved visibility while suppressing an increase in the amount of radiation exposure of a subject.

[0008] According to one aspect of the present invention, there is provided an X-ray fluoroscopy apparatus comprising: an X-ray irradiator that irradiates X-rays; an X-ray detector that detects the X-rays irradiated by the X-ray irradiator; an operation unit that accepts input operations related to the irradiation of X-rays by the X-ray irradiator; and a controller that controls the X-ray irradiator to irradiate X-rays based on the input operations of the operation unit and generates an X-ray image based on a detection signal output from the X-ray detector, wherein the controller is configured to stop the X-ray irradiation by the X-ray irradiator when the pixel values ​​of pixels included in the generated X-ray image are within a range of target pixel values, even if the operation unit continues to accept the input operations to irradiate X-rays.

[0009] In the X-ray fluoroscopy apparatus according to the first aspect, as described above, the control unit is configured to stop X-ray irradiation by the X-ray irradiator when the pixel value of a pixel included in the generated X-ray image falls within a target pixel value range, even if the operation unit continues to accept an input operation for X-ray irradiation. As a result, even if the input operation for X-ray irradiation continues to be accepted, X-ray irradiation by the X-ray irradiator is stopped when the pixel value of a pixel included in the generated X-ray image falls within the target pixel value range. This prevents the X-ray irradiation input operation from being canceled before the pixel value falls within the target pixel value range, due to concerns about an increase in the subject's radiation exposure. It also prevents an increase in X-ray irradiation time due to continued acceptance of the input operation for X-ray irradiation when the pixel value falls within the target pixel value range. Furthermore, when the control unit stops X-ray irradiation, the pixel value of the pixel included in the generated X-ray image falls within the target pixel value range, thereby improving the visibility of the generated X-ray image. For these reasons, an X-ray image with improved visibility can be obtained while suppressing an increase in the subject's radiation exposure.

[0010] FIG. 1 is a block diagram showing the configuration of an X-ray fluoroscopy apparatus according to a first embodiment. FIG. 2 is a schematic diagram of an X-ray fluoroscopy apparatus according to the first embodiment. FIG. 3 is a schematic diagram of a foot switch and an operation panel of an X-ray fluoroscopy apparatus according to the first embodiment. FIG. 4 is a schematic diagram of a display unit of an X-ray fluoroscopy apparatus according to the first embodiment. FIG. 5 is a diagram showing an example of an APR according to the first embodiment. FIG. 6 is a sequence diagram for explaining feedback control using a first operation unit according to the first embodiment. FIG. 7 is a sequence diagram for explaining feedback control using a second operation unit according to the first embodiment. FIG. 8 is a first flowchart for explaining pixel value adjustment processing and X-ray image display processing according to the first embodiment. FIG. 9 is a second flowchart for explaining pixel value adjustment processing and X-ray image display processing according to the first embodiment. FIG. 10 is a block diagram showing the configuration of an X-ray fluoroscopy apparatus according to a second embodiment. FIG. 11 is a schematic diagram of a foot switch and an operation panel of an X-ray fluoroscopy apparatus according to the second embodiment. FIG. 12 is a third flowchart for explaining pixel value adjustment processing and X-ray image display processing according to the second embodiment. FIG. 13 is a fourth flowchart for explaining pixel value adjustment processing and X-ray image display processing according to the second embodiment.

[0011] First Embodiment (Configuration of X-ray Fluoroscopy Apparatus) The configuration of an X-ray fluoroscopy apparatus 100 according to a first embodiment will be described with reference to FIGS. 1 to 5. FIG.

[0012] The X-ray fluoroscopy apparatus 100 is an X-ray fluoroscopy apparatus used to take X-ray images when a doctor or other professional performs a surgical procedure. As shown in FIGS. 1 and 2 , the X-ray fluoroscopy apparatus 100 includes an apparatus main body 1 and a monitor cart 4. The entire X-ray fluoroscopy apparatus 100 is movable, and is configured to be able to move to a subject in an operating room and take X-ray images when a doctor or other professional performs a procedure. Note that X-ray photography includes fluoroscopy, which captures X-ray images as moving images, and general photography, which captures X-ray images as still images. Furthermore, X-ray images include X-ray fluoroscopy images and general X-ray images.

[0013] 1, the device main body 1 includes an X-ray imaging unit 2, an operation unit 3, a storage unit 5, a control unit 6, a movement mechanism unit 7 (see FIG. 2), and an arm 8 (see FIG. 2). The X-ray imaging unit 2 includes an X-ray irradiation unit 21 and an X-ray detection unit 22. The monitor cart 4 includes a display unit 4a.

[0014] When the X-ray fluoroscopic imaging apparatus 100 is used to image a subject, the subject (not shown) and a tabletop (not shown) on which the subject rests are placed are placed inside the arm 8 (see FIG. 2). The tabletop is the tabletop of a bed used by the subject in an operating room or the like.

[0015] 1, the X-ray irradiator 21 is configured to generate X-rays when a high voltage is applied thereto and to irradiate the generated X-rays toward the X-ray detector 22. The X-ray irradiator 21 includes, for example, an X-ray tube which is an X-ray source, and a collimator which adjusts the irradiation range of the X-rays generated by the X-ray tube.

[0016] The X-ray detection unit 22 is configured to detect X-rays irradiated by the X-ray irradiation unit 21. The X-ray detection unit 22 includes, for example, a flat panel detector (FPD). The X-ray detection unit 22 transmits a detection signal, which is an electrical signal corresponding to the detected X-rays, to an image processing unit 61, which will be described later. Note that the X-ray detection unit 22 may include an image intensifier (II) instead of an FPD.

[0017] The operation unit 3 is configured to accept input operations related to X-ray irradiation by the X-ray irradiator 21. The operation unit 3 includes a first operation unit 3a and a second operation unit 3b for performing fluoroscopic imaging. When an input operation for X-ray irradiation is accepted by the first operation unit 3a, if the pixel values ​​of the generated X-ray image are within the range of the target pixel value 58 (see FIG. 5), the X-ray irradiation by the X-ray irradiator 21 is stopped even if the acceptance of the input operation continues. On the other hand, when an input operation for X-ray irradiation is accepted by the second operation unit 3b, the X-ray irradiation by the X-ray irradiator 21 is not stopped even if the pixel values ​​of the generated X-ray image are within the range of the target pixel value 58.

[0018] The operation unit 3 includes a foot switch 70 (see FIG. 3A) and an operation panel 33 (see FIG. 3B).

[0019] 3( a), the foot switch 70 includes a first foot switch 71 serving as a first operation unit 3a used for performing fluoroscopic imaging, a second foot switch 72 serving as a second operation unit 3b used for performing fluoroscopic imaging, and a third foot switch 73 used for performing general imaging. The foot switch 70 is configured to accept input operations related to the start and end of X-ray irradiation by the X-ray irradiator 21. When the first foot switch 71 or the second foot switch 72 is depressed, X-ray irradiation from the X-ray irradiator 21 is initiated, thereby starting X-ray fluoroscopy. When the foot is released from the depressed first foot switch 71 or the second foot switch 72, X-ray irradiation from the X-ray irradiator 21 is stopped, thereby ending X-ray fluoroscopy. While the first foot switch 71 or the second foot switch 72 is depressed, X-ray fluoroscopy continues, and X-ray images collected at a predetermined frame rate are displayed as a moving image on the display unit 4a. When an input operation to irradiate X-rays is accepted by the first foot switch 71, if the pixel values ​​of the generated X-ray image are within the range of the target pixel value 58 (see FIG. 5), the X-ray irradiation unit 21 stops irradiating X-rays even if the acceptance of the input operation continues. When the third foot switch 73 is depressed, X-rays are irradiated from the X-ray irradiation unit 21, thereby performing general radiography. The foot switch 70 is connected to the device main body via a cable 70a.

[0020] As shown in Fig. 3(b), the operation panel 33 is provided with a plurality of input units 33a that accept input operations related to X-ray irradiation. The input units 33a include an X-ray fluoroscopy button 36a and a target pixel value change button 37. The operation panel 33 may be configured as, for example, a touch panel type liquid crystal display that functions as an input unit into which various operations are input. The operation panel 33 is provided on the movement mechanism unit 7 (see Fig. 2).

[0021] The X-ray fluoroscopy button 36a includes a first X-ray fluoroscopy button 34 serving as the first operation unit 3a and a second X-ray fluoroscopy button 35 serving as the second operation unit 3b. The X-ray fluoroscopy button 36a is configured to accept input operations related to the start and end of X-ray irradiation by the X-ray irradiator 21. When the X-ray fluoroscopy button 36a is pressed, X-ray fluoroscopy is started by irradiating X-rays from the X-ray irradiator 21. When the X-ray fluoroscopy button 36a is released, X-ray irradiation from the X-ray irradiator 21 is stopped and X-ray fluoroscopy is ended. While the X-ray fluoroscopy button 36a is pressed, X-ray fluoroscopy continues, and X-ray images collected at a predetermined frame rate are displayed as a moving image on the display unit 4a. In addition, when an input operation to irradiate X-rays is accepted using the first X-ray fluoroscopy button 34, if the pixel value of the generated X-ray image is within the range of the target pixel value 58 (see Figure 5), the X-ray irradiation unit 21 will stop irradiating X-rays even if the input operation continues to be accepted.

[0022] The target pixel value change button 37 is configured to receive an input operation for changing the set target pixel value 58, which will be described later. The target pixel value change button 37 includes a plus button 37a that gradually increases the brightness level of the X-ray image to be generated, and a minus button 37b that gradually decreases the brightness level of the X-ray image to be generated, based on the brightness level of the X-ray image corresponding to the set target pixel value 58.

[0023] That is, the set target pixel value 58 is changed to be larger based on the operation of the plus button 37a. By changing the set target pixel value 58 to be larger, the tube voltage 55 or the tube current 56 included in the set X-ray irradiation conditions 54 (see FIG. 5) is increased. As a result, the brightness level of the generated X-ray image increases and the radiation exposure dose of the subject increases.

[0024] Furthermore, the set target pixel value 58 is changed to be smaller based on the operation of the minus button 37b. By changing the set target pixel value 58 to be smaller, the tube voltage 55 or the tube current 56 included in the set X-ray irradiation conditions 54 (see FIG. 5) is reduced. As a result, the brightness level of the generated X-ray image is lowered and the radiation exposure of the subject is reduced.

[0025] As shown in FIG. 1 , the storage unit 5 includes a ROM (Read Only Memory) or a RAM (Random Access Memory). Various programs executed by the processor are stored in the storage unit 5. The storage unit 5 also stores X-ray images generated at a predetermined frame rate. The X-ray images stored in the storage unit 5 include multiple frame images generated from the start of X-ray fluoroscopy to the end of X-ray fluoroscopy. The generated X-ray images are configured to be stored as still images or moving images.

[0026] 5, the storage unit 5 also stores an APR (Anatomical Program) 50. The APR 50 is a program in which image acquisition conditions 52 are linked to each piece of body part information 51. The body part information 51 is information about the body part of the subject to be irradiated with X-rays, and examples include the head and neck, chest, abdomen, hip joints, shoulders, knees, and feet. The image acquisition conditions 52 are a series of conditions related to the acquisition of X-ray images, and include X-ray irradiation conditions 54 and image processing conditions 53.

[0027] The X-ray irradiation conditions 54 are various parameters related to X-ray irradiation. Examples of the parameters related to X-ray irradiation include a tube voltage 55 and a tube current 56 applied to the X-ray tube. The image processing conditions 53 are parameters related to image processing performed on the detection signal, which is an electrical signal transmitted by the X-ray detection unit 22, and examples thereof include a contrast processing value, a sharpening processing value, and an edge processing value. The image processing conditions 53 also include a frame rate 57.

[0028] The control unit 6 is configured by a processor such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an FPGA (Field-Programmable Gate Array), or an ASIC (Application Specific Integrated Circuit). The control unit 6 as hardware includes, as software (program) functional blocks, an image processing unit 61, an imaging control unit 60, and a display control unit 62. The control unit 6 functions as the image processing unit 61, the imaging control unit 60, and the display control unit 62 by executing a program stored in the storage unit 5. The image processing unit 61, the imaging control unit 60, and the display control unit 62 may be configured individually as hardware by providing a dedicated processor (processing circuit).

[0029] The image processing unit 61 is configured to generate an X-ray image based on the detection signal output from the X-ray detection unit 22. The image processing unit 61 is configured to sequentially generate X-ray images. The image processing unit 61 is configured to sequentially generate X-ray images of the inside of the subject at a predetermined frame rate (for example, about several fps to a dozen fps).

[0030] The image processing unit 61 is also configured to acquire the pixel value of each pixel included in the generated X-ray image. The image processing unit 61 is also configured to acquire the average, maximum, and minimum pixel values ​​of each pixel in a specific region 59 (see FIG. 5) included in the generated X-ray image. The specific region 59 is a region set in advance in each part of the subject to be irradiated with X-rays, and is information included in the APR 50 (see FIG. 5). In the first embodiment, for example, the generated X-ray image is image data having pixel values ​​of 4096 gradations (12 bits) from 0 to 4095. A pixel with a pixel value of the minimum gradation 0 has a display density of black, and a pixel with a pixel value of the maximum gradation 4095 has a display density of white.

[0031] The imaging control unit 60 is configured to control the X-ray irradiation by the X-ray irradiator 21 based on an input operation of the operation unit 3. When the pixel value of a pixel included in the X-ray image generated by the image processing unit 61 is within the range of a target pixel value 58 (see FIG. 5), the imaging control unit 60 is configured to stop the X-ray irradiation by the X-ray irradiator 21 even if the input operation for irradiating X-rays is still being accepted by the first operation unit 3a.

[0032] Furthermore, when the pixel values ​​of the X-ray image generated by the image processing unit 61 are not within the range of the target pixel values ​​58 (see FIG. 5), the imaging control unit 60 is configured to change the set X-ray irradiation conditions 54 and cause the X-ray irradiation unit 21 to irradiate X-rays in order to adjust the pixel values ​​of the pixels included in the X-ray image.

[0033] Specifically, the imaging control unit 60 obtains the differences between the average value, maximum value, and minimum value of the pixel values ​​of each pixel in the specific region 59 obtained by the image processing unit 61 and the average value, maximum value, and minimum value of the pixel values ​​in the target pixel value 58. The imaging control unit 60 changes the set X-ray irradiation conditions 54 in accordance with the obtained differences, and causes the X-ray irradiator 21 to irradiate X-rays. The imaging control unit 60 performs feedback control to cause the X-ray irradiator 21 to irradiate X-rays by adjusting the tube voltage or tube current supplied to the X-ray tube, for example, so that the obtained differences approach zero.

[0034] Alternatively, the imaging control unit 60 acquires the ratios of the average value, maximum value, and minimum value of pixel values ​​in the target pixel value 58 to the average value, maximum value, and minimum value of pixel values ​​of each pixel in the specific region 59 acquired by the image processing unit 61. The imaging control unit 60 changes the set X-ray irradiation conditions 54 in accordance with the acquired ratios, and causes the X-ray irradiator 21 to irradiate X-rays. For example, the imaging control unit 60 performs feedback control to adjust the tube voltage or tube current supplied to the X-ray tube so that the acquired ratio approaches 1, causing the X-ray irradiator 21 to irradiate X-rays.

[0035] In addition, the imaging control unit 60 is configured to stop the X-ray irradiation by the X-ray irradiation unit 21 when the pixel values ​​of the X-ray image generated by the image processing unit 61 based on the changed X-ray irradiation conditions 54 are within the range of the target pixel values ​​58, even if the first operation unit 3a continues to accept input operations to irradiate X-rays.

[0036] In addition, the imaging control unit 60 is configured to stop the X-ray irradiation by the X-ray irradiation unit 21 when the pixel values ​​in the set multiple X-ray images are within the range of the target pixel value 58, even if the first operation unit 3a continues to accept input operations to irradiate X-rays.

[0037] As an example, the imaging control unit 60 is configured to stop X-ray irradiation by the X-ray irradiator 21 when pixel values ​​in five consecutive frames of X-ray images fall within the range of the target pixel value 58, even if the first operation unit 3a continues to accept an input operation to irradiate X-rays. The set multiple X-ray images are not limited to five consecutive frames. For example, they may be two to four consecutive frames, or six or more consecutive frames. They may also be multiple non-consecutive X-ray images. In the first embodiment, the imaging control unit 60 causes the X-ray irradiator 21 to irradiate X-rays without changing the X-ray irradiation conditions 54 until pixel values ​​in five consecutive frames of X-ray images fall within the range of the target pixel value 58.

[0038] The display control unit 62 is configured to cause the display unit 4a to display a message that enables the user to recognize that the X-ray irradiation by the X-ray irradiation unit 21 has been stopped, even if the first operation unit 3a continues to accept input operations to irradiate X-rays, based on the fact that the X-ray irradiation by the X-ray irradiation unit 21 has been stopped because the pixel values ​​in multiple X-ray images are included within the range of the target pixel value 58, by the imaging control unit 60.

[0039] Specifically, the display control unit 62 is configured to cause the display unit 4a to recognizably display that the last X-ray image of the generated X-ray images at the time when X-ray irradiation was stopped is displayed on the display unit 4a as a recognizable display of the stop of X-ray irradiation by the X-ray irradiator 21. More specifically, based on the fact that the X-ray irradiation by the X-ray irradiator 21 has been stopped because the pixel values ​​of the multiple X-ray images fall within the range of the target pixel value 58, the display control unit 62 causes the display unit 4a to display the last X-ray image of the generated X-ray images at the time when X-ray irradiation was stopped (last image hold image) and an indicator 41 (see FIG. 4 ) that allows the user to recognize that the X-ray image displayed on the display unit 4a is the last image hold image.

[0040] The moving mechanism 7 is configured to be movable while supporting the X-ray imaging unit 2 and the arm 8. The moving mechanism 7 is configured as a carriage for the X-ray fluoroscopy apparatus 100. The moving mechanism 7 is also provided with a plurality of wheels 7a, an arm support 7b, and a connecting portion 7c.

[0041] The plurality of wheels 7a are provided on the lower part of the moving mechanism unit 7. This makes it possible to move the X-ray fluoroscopy apparatus 100. In other words, the X-ray fluoroscopy apparatus 100 is a mobile (portable) imaging apparatus.

[0042] The arm support section 7b slidably supports the arm 8. The arm support section 7b is also disposed on the movement mechanism section 7 and is connected to a connecting section 7c that rotates the arm support section 7b together with the arm 8 and the like around a horizontal axis. The connecting section 7c rotates around a vertical axis relative to the movement mechanism section 7. Therefore, as the connecting section 7c rotates, the arm 8 rotates around the vertical axis together with the X-ray irradiation section 21 and the X-ray detection section 22.

[0043] The arm 8 holds an X-ray irradiation unit 21 at one end thereof. The arm 8 holds an X-ray detection unit 22 at the other end thereof. The arm 8 has a C-shape. The arm 8 is a so-called C-arm.

[0044] The monitor cart unit 4 includes a display unit 4a and a plurality of wheels 4b. The monitor cart unit 4 is configured to be movable by the plurality of wheels 4b.

[0045] The display unit 4a is configured to display the X-ray image of the subject generated by the image processing unit 61. The display unit 4a includes, for example, a liquid crystal monitor. As shown in Fig. 4, the X-ray image generated at a predetermined frame rate is displayed in real time as a moving image in an image display area 40 of the display unit 4a.

[0046] 4, a last image hold image is displayed in the image display area 40 of the display unit 4a. When the last image hold image is displayed, a sign 41 indicating that the image is the last image hold image is recognizably displayed on the display unit 4a in the image display area 40 of the display unit 4a. For example, "LIH" is displayed on the display unit 4a as the sign 41 indicating that the image is the last image hold image.

[0047] Furthermore, the display unit 4a displays a level image 42 indicating the brightness level of the X-ray image to be generated, based on the brightness level of the X-ray image corresponding to the set target pixel value 58. As an example, when the brightness of the X-ray image corresponding to the set target pixel value 58 is at the reference level, an image of "0" is displayed as shown in Fig. 4, when the brightness level of the X-ray image to be generated is increased by one level from the reference level, an image of "+1" is displayed, and when the brightness level of the X-ray image to be generated is decreased by one level from the reference level, an image of "-1" is displayed.

[0048] (Pixel Value and Target Pixel Value) The pixel value includes the average value, maximum value, and minimum value of the pixel value of each pixel in the specific region 59 (see FIG. 5) included in the X-ray image generated by the image processing unit 61.

[0049] The target pixel value 58 is information included in the APR 50 (see FIG. 5 ). The target pixel value 58 includes the average value, maximum value, and minimum value of the pixel values ​​of each pixel in a specific region 59 set in each imaging region of the subject. A specific range centered on the target pixel value 58 is set in advance as the range of the target pixel value 58. For example, a range including plus or minus several percent from the target pixel value 58 is set in advance as the range of the target pixel value 58. The set target pixel value 58 is also configured to be changeable. Specifically, the target pixel value change button 37 is configured to allow the level of the set target pixel value 58 to be increased or decreased.

[0050] (First Operation Unit and Second Operation Unit) When an input operation for irradiating X-rays is accepted by the first operation unit 3a, if the pixel value of the generated X-ray image is included in the range of the target pixel value 58, the imaging control unit 60 is configured to stop the X-ray irradiation by the X-ray irradiator 21 even if the input operation for irradiating X-rays continues to be accepted by the first operation unit 3a. In this case, the image processing unit 61 is configured to stop the generation of the X-ray image.

[0051] On the other hand, when an input operation to irradiate X-rays is received by the second operation unit 3b, the imaging control unit 60 is configured not to stop the irradiation of X-rays by the X-ray irradiator 21 even if the pixel values ​​of the generated X-ray image are within the range of the target pixel values ​​58. In this case, the image processing unit 61 is configured to generate an X-ray image.

[0052] The X-ray fluoroscopy apparatus 100 of this embodiment is a surgical X-ray fluoroscopy apparatus. Surgical X-ray fluoroscopy apparatuses are sometimes used in orthopedic applications to check the implantation status of bolts in the lower back of a subject or the implantation status of plates in the arms of a subject. In these cases, the body thickness of the lower back and the arms differ. Therefore, when acquiring a last image hold image for confirmation, a surgical X-ray fluoroscopy apparatus has a problem in that it is difficult to optimize the depression time of the foot switch due to the difference in body thickness for each imaging region. With the configuration of this embodiment, even if the body thickness differs for each imaging region, X-ray irradiation by the X-ray irradiator 21 is stopped when the pixel value of a pixel included in the generated X-ray image falls within the range of the target pixel value 58, even if an input operation for X-ray irradiation continues to be accepted. Therefore, it is possible to prevent the acceptance of the input operation for X-ray irradiation from being canceled before the pixel value falls within the range of the target pixel value 58 due to concerns about an increase in the radiation exposure dose of the subject, and it is also possible to prevent an increase in the X-ray irradiation time due to the continuation of the acceptance of the input operation for X-ray irradiation when the pixel value falls within the range of the target pixel value 58. Therefore, even if the body thickness (thickness) differs for each imaging region, the depression time of the foot switch can be optimized.

[0053] (Example of feedback control when input operation is accepted by first operating unit) Referring to Figure 6, an example of feedback control in X-ray fluoroscopy according to the first embodiment when input operation is accepted by the first operating unit 3a will be described based on a sequence diagram.

[0054] In step S1, the imaging control unit 60 accepts an input operation to the first operation unit 3a. Note that, in the processes of steps S1 to S13, the acceptance of the input operation to the first operation unit 3a continues. Also, in the processes of steps S1 to S13, if the acceptance of the input operation to the first operation unit 3a is canceled, the process ends.

[0055] In step S2, the imaging control unit 60 transmits an X-ray fluoroscopy start signal based on the set X-ray irradiation conditions 54 to the X-ray imaging unit 2. Then, the X-ray imaging unit 2 acquires the X-ray fluoroscopy start signal based on the set X-ray irradiation conditions 54.

[0056] In step S3, the X-ray irradiator 21 of the X-ray imaging unit 2 irradiates X-rays based on the set X-ray irradiation conditions 54, and the X-ray detector 22 of the X-ray imaging unit 2 acquires a detection signal.

[0057] In step S4, the acquired detection signal is transmitted from the X-ray detection unit 22 of the X-ray imaging unit 2 to the image processing unit 61. Then, the image processing unit 61 acquires the detection signal.

[0058] In step S5, the image processing unit 61 generates an X-ray image based on the detection signal obtained from the X-ray detection unit 22, and obtains the average, maximum, and minimum pixel values ​​of each pixel in a specific region 59 included in the X-ray image.

[0059] In step S6, the image processing unit 61 transmits the average, maximum, and minimum pixel values ​​of each pixel in the acquired specific region 59 to the imaging control unit 60. Then, the imaging control unit 60 acquires the average, maximum, and minimum pixel values ​​of each pixel in the specific region 59.

[0060] In step S7, if the average value, maximum value, and minimum value of the pixel values ​​of each pixel in the acquired specific region 59 are within the range of the average value, maximum value, and minimum value of the pixel values ​​as the target pixel value 58, the process proceeds to step S8. On the other hand, if the average value, maximum value, and minimum value of the pixel values ​​of each pixel in the acquired specific region 59 are not within the range of the average value, maximum value, and minimum value of the pixel values ​​as the target pixel value 58, the process proceeds to step S11.

[0061] In step S8, if the pixel values ​​of five consecutive frames of X-ray images are within the range of the target pixel value 58, the process proceeds to step S9. If there are fewer than five consecutive frames of X-ray images whose pixel values ​​are within the range of the target pixel value 58, the process proceeds to step S13.

[0062] In step S9, the imaging control unit 60 transmits an X-ray fluoroscopy end signal to the X-ray imaging unit 2. Then, the X-ray imaging unit 2 acquires the X-ray fluoroscopy end signal.

[0063] In step S10, the X-ray imaging unit 2 ends the X-ray fluoroscopic imaging.

[0064] In step S11, the imaging control unit 60 changes the set X-ray irradiation conditions 54.

[0065] In step S12, the imaging control unit 60 transmits an X-ray fluoroscopy start signal based on the changed X-ray irradiation conditions 54 to the X-ray imaging unit 2. Then, the process proceeds to step S3, where the X-ray imaging unit 2 acquires the X-ray fluoroscopy start signal based on the changed X-ray irradiation conditions 54.

[0066] In step S13, the imaging control unit 60 transmits an X-ray fluoroscopy imaging start signal based on the X-ray irradiation conditions 54 that have been maintained unchanged to the X-ray imaging unit 2. Then, the process proceeds to step S3, where the X-ray imaging unit 2 acquires the X-ray fluoroscopy imaging start signal based on the X-ray irradiation conditions 54 that have been maintained unchanged.

[0067] (Example of feedback control when input operation is accepted by second operating unit) Referring to Figure 7, an example of feedback control in X-ray fluoroscopy when input operation is accepted by the second operating unit 3b according to the first embodiment will be described based on a sequence diagram.

[0068] In step S21, the imaging control unit 60 accepts an input operation to the second operation unit 3b. Note that the acceptance of the input operation to the second operation unit 3b continues in the processes of steps S21 to S30. Furthermore, if the acceptance of the input operation to the second operation unit 3b is canceled in the processes of steps S21 to S30, the process ends.

[0069] The processing of steps S22 to S30 is the same as the processing of steps S2 to S7 and steps S11 to S13 in the feedback control of X-ray fluoroscopy when an input operation is accepted by the first operation unit 3a, and therefore a description thereof will be omitted. Note that the processing of steps S23 to S30 is repeated until acceptance of an input operation by the second operation unit 3b is canceled.

[0070] (X-ray image pixel value adjustment processing and X-ray image display processing) The X-ray image pixel value adjustment processing and X-ray image display processing by the control unit 6 according to the first embodiment will be described with reference to Figures 8 and 9. The X-ray image pixel value adjustment processing and X-ray image display processing by the control unit 6 are started based on the reception of an input operation related to X-ray irradiation by the operation unit 3.

[0071] Furthermore, in the processing of steps S101 to S110, the first operation unit 3a continues to receive input operations. In the processing of steps S101 to S110, if the reception of input operations to the first operation unit 3a is canceled, the processing ends. In the processing of steps S111 to S116 and S119, the second operation unit 3b continues to receive input operations. In the processing of steps S111 to S116 and S119, if the reception of input operations to the second operation unit 3b is canceled, the processing ends. Note that the order of the processing steps can be reversed or executed simultaneously, as long as there are no contradictions between them.

[0072] In step S101, the imaging control unit 60 determines whether an input operation related to X-ray irradiation has been accepted by the first operation unit 3 a or the second operation unit 3 b. If an input operation related to X-ray irradiation has been accepted by the first operation unit 3 a, the process proceeds to step S102. If an input operation related to X-ray irradiation has been accepted by the second operation unit 3 b, the process proceeds to step S111 in FIG. 9 .

[0073] In step S102, the imaging control unit 60 causes the X-ray imaging unit 2 to start X-ray fluoroscopic imaging based on the set X-ray irradiation conditions 54 or the changed X-ray irradiation conditions 54. Thereafter, the process proceeds to step S103.

[0074] In step S103, the image processing unit 61 generates an X-ray image based on the detection signal output from the X-ray detection unit 22. Thereafter, the process proceeds to step S104.

[0075] In step S104, the display control unit 62 causes the display unit 4a to display the X-ray image generated by the image processing unit 61. Thereafter, the process proceeds to step S105.

[0076] In step S105, the image processing unit 61 obtains the average value, maximum value, and minimum value of the pixel value of each pixel in the specific region 59 included in the generated X-ray image. Thereafter, the process proceeds to step S106.

[0077] In step S106, if the average value, maximum value, and minimum value of the pixel values ​​of each pixel in the specific area 59 acquired by the image processing unit 61 in the shooting control unit 60 are within the range of the target pixel value 58 (Yes in step S106), the processing proceeds to step S107, and if the average value, maximum value, and minimum value of the pixel values ​​of each pixel in the specific area 59 acquired by the image processing unit 61 are not within the range of the target pixel value 58 (No in step S106), the processing proceeds to step S110.

[0078] In step S107, if the imaging control unit 60 determines that the pixel values ​​of five consecutive frames of X-ray images are within the range of the target pixel value 58 (Yes in step S107), the process proceeds to step S108, and if there are fewer than five consecutive frames of X-ray images whose pixel values ​​are within the range of the target pixel value 58 (No in step S107), the process proceeds to step S103. Note that when proceeding to step S103, the X-ray irradiation conditions 54 are not changed.

[0079] In step S108, the imaging control unit 60 ends the X-ray fluoroscopic imaging by the X-ray imaging unit 2. After that, the process proceeds to step S109.

[0080] In step S109, the display control unit 62 causes the display unit 4a to display the last image hold image and "LIH," which allows the user to recognize that the X-ray image displayed on the display unit 4a is the last image hold image. Then, the process ends.

[0081] In step S110, the imaging control unit 60 changes the set X-ray irradiation conditions 54, or, if the set X-ray irradiation conditions 54 have already been changed, changes the changed X-ray irradiation conditions 54. Thereafter, the process proceeds to step S103.

[0082] In step S111, the imaging control unit 60 causes the X-ray imaging unit 2 to start X-ray fluoroscopic imaging based on the set X-ray irradiation conditions 54 or the changed X-ray irradiation conditions 54. Thereafter, the process proceeds to step S112.

[0083] In step S112, the image processing unit 61 generates an X-ray image based on the detection signal output from the X-ray detection unit 22. Thereafter, the process proceeds to step S113.

[0084] In step S113, the display control unit 62 causes the display unit 4a to display the X-ray image generated by the image processing unit 61. Thereafter, the process proceeds to step S114.

[0085] In step S114, the image processing unit 61 obtains the average value, maximum value, and minimum value of the pixel value of each pixel in the specific region 59 included in the generated X-ray image. Thereafter, the process proceeds to step S115.

[0086] In step S115, if the shooting control unit 60 determines that the average, maximum, and minimum pixel values ​​of each pixel in the specific area 59 acquired by the image processing unit 61 are within the range of the target pixel value 58 (Yes in step S115), the processing proceeds to step S116; if the average, maximum, and minimum pixel values ​​of each pixel in the specific area 59 acquired by the image processing unit 61 are not within the range of the target pixel value 58 (No in step S115), the processing proceeds to step S119.

[0087] In step S116, the imaging control unit 60 determines whether the second operation unit 3b is continuing to accept input operations related to X-ray irradiation. If the second operation unit 3b is continuing to accept input operations related to X-ray irradiation (Yes in step S116), the process proceeds to step S112. If the second operation unit 3b is not continuing to accept input operations related to X-ray irradiation (i.e., if the input operations related to X-ray irradiation by the second operation unit 3b have been canceled) (No in step S116), the process proceeds to step S117. Note that when proceeding to step S112, the X-ray irradiation conditions 54 are not changed.

[0088] In step S117, the imaging control unit 60 ends the X-ray fluoroscopic imaging by the X-ray imaging unit 2. After that, the process proceeds to step S118.

[0089] In step S118, the display control unit 62 causes the display unit 4a to display the last image hold image and "LIH," which allows the user to recognize that the X-ray image displayed on the display unit 4a is the last image hold image. Then, the process ends.

[0090] In step S119, the imaging control unit 60 changes the set X-ray irradiation conditions 54, or, if the set X-ray irradiation conditions 54 have already been changed, changes the changed X-ray irradiation conditions 54. Thereafter, the process proceeds to step S112.

[0091] (Effects of First Embodiment) In the first embodiment, the following effects can be obtained.

[0092] As described above, in the first embodiment, the imaging control unit 60 is configured to stop X-ray irradiation by the X-ray irradiator 21 when the pixel value of a pixel included in the generated X-ray image falls within the range of the target pixel value 58, even if the first operation unit 3 a continues to accept an input operation to irradiate X-rays. As a result, even if the input operation to irradiate X-rays continues to be accepted, X-ray irradiation by the X-ray irradiator 21 is stopped when the pixel value of a pixel included in the generated X-ray image falls within the range of the target pixel value 58. This makes it possible to prevent the acceptance of the input operation for X-ray irradiation from being canceled before the pixel value falls within the range of the target pixel value 58, due to concerns about an increase in the subject's radiation exposure, and to prevent an increase in the X-ray irradiation time due to continued acceptance of the input operation for X-ray irradiation when the pixel value falls within the range of the target pixel value 58. Furthermore, when X-ray irradiation is stopped by the imaging control unit 60, the pixel value of the pixel included in the generated X-ray image falls within the range of the target pixel value 58, thereby improving the visibility of the generated X-ray image. For these reasons, it is possible to obtain X-ray images with improved visibility while suppressing an increase in the amount of radiation exposure to the subject.

[0093] Furthermore, in the first embodiment, the following additional effects can be obtained by configuring as follows.

[0094] That is, in the first embodiment, as described above, the imaging control unit 60 is configured to change the set X-ray irradiation conditions 54 and cause the X-ray irradiator 21 to irradiate X-rays in order to adjust the pixel values ​​of the pixels included in the X-ray image when the pixel values ​​of the generated X-ray image are not within the range of the target pixel values ​​58, and to stop the X-ray irradiation by the X-ray irradiator 21 when the pixel values ​​of the X-ray image generated based on the changed X-ray irradiation conditions 54 are within the range of the target pixel values ​​58, even if the first operation unit 3 a continues to accept an input operation to irradiate X-rays. In this way, the X-ray irradiation conditions 54 are changed so that the pixel values ​​of the generated X-ray image are within the range of the target pixel values ​​58, making it possible to easily generate an X-ray image whose pixel values ​​are within the range of the target pixel values ​​58. Therefore, it is possible to easily obtain an X-ray image with improved visibility.

[0095] Furthermore, in the first embodiment, as described above, the display unit 4a that displays the X-ray image is further provided, and the display control unit 62 is configured to cause the display unit 4a to execute a display that allows the user to recognize that the X-ray irradiation by the X-ray irradiator 21 has been stopped, even if the first operation unit 3a continues to accept an input operation to irradiate X-rays, based on the fact that the pixel values ​​in the X-ray image fall within the range of the target pixel value 58. This allows the user to easily visually recognize that the X-ray irradiation has been stopped because the pixel values ​​in the X-ray image fall within the range of the target pixel value 58.

[0096] Furthermore, in the first embodiment, as described above, the display control unit 62 is configured to cause the display unit 4a to display, in a recognizable manner, the last X-ray image when X-ray irradiation was stopped among the generated X-ray images, as a recognizable display of the stop of X-ray irradiation by the X-ray irradiator 21, thereby causing the display unit 4a to execute a display that allows the user to recognize that X-ray irradiation by the X-ray irradiator 21 has been stopped. This allows the user to visually recognize more easily that X-ray irradiation has been stopped because the pixel values ​​in the X-ray image are included within the range of the target pixel value 58, based on the display of the last X-ray image when X-ray irradiation was stopped and the X-ray image.

[0097] Furthermore, in the first embodiment, as described above, the image processing unit 61 is configured to sequentially generate X-ray images, and the imaging control unit 60 is configured to stop the X-ray irradiation by the X-ray irradiator 21 when pixel values ​​in the set plurality of X-ray images fall within the range of the target pixel value 58, even if the first operation unit 3a continues to accept an input operation to irradiate X-rays. This makes it possible to prevent the X-ray irradiation by the X-ray irradiator 21 from being stopped when a pixel value in one X-ray image accidentally falls within the range of the target pixel value 58 due to body movement of the subject, etc. This makes it possible to improve the accuracy of acquiring X-ray images with improved visibility.

[0098] Furthermore, in the first embodiment, as described above, the operation unit 3 includes the first operation unit 3a and the second operation unit 3b, and the imaging control unit 60 is configured to stop the irradiation of X-rays by the X-ray irradiator 21 and stop the generation of the X-ray image when an input operation to irradiate X-rays is accepted by the first operation unit 3a and the pixel values ​​of the generated X-ray image are within the range of the target pixel value 58, even if the input operation to irradiate X-rays continues to be accepted by the first operation unit 3a; and to not stop the irradiation of X-rays by the X-ray irradiator 21 and to continue generating the X-ray image when an input operation to irradiate X-rays is accepted by the second operation unit 3b and the pixel values ​​of the generated X-ray image are within the range of the target pixel value 58. This allows the user to appropriately select, depending on the purpose of use, between the first operation unit 3a, which stops the X-ray irradiation by the X-ray irradiation unit 21 even if the input operation for X-ray irradiation continues to be accepted, and the second operation unit 3b, which causes the X-ray irradiation unit 21 to irradiate X-rays as long as the input operation for X-ray irradiation continues to be accepted, thereby improving user convenience (usability).

[0099] Furthermore, in the first embodiment, as described above, the pixel values ​​include the average value, maximum value, and minimum value of the pixel values ​​of each pixel in the specific region 59 included in the X-ray image generated by the image processing unit 61, and the target pixel value 58 includes the average value, maximum value, and minimum value of the pixel values ​​of each pixel in the specific region 59 set for each imaging region of the subject. As a result, when the pixel values ​​of the pixels included in the generated X-ray image are within the range of the target pixel value 58, the average value, maximum value, and minimum value of the pixel values ​​of each pixel in the specific region 59 included in the X-ray image are each included in the desired range, thereby improving the accuracy of acquiring X-ray images with improved visibility.

[0100] Furthermore, in the first embodiment, as described above, the range of the target pixel value 58 is a specific range that is set in advance and is centered around the target pixel value 58. As a result, by providing a certain width around the target pixel value 58 when halting X-ray irradiation by the X-ray irradiator 21, it is possible to appropriately halt X-ray irradiation by the X-ray irradiator 21 when the pixel value in the X-ray image is included in an allowable range centered around the target pixel value 58.

[0101] Furthermore, as described above, the first embodiment is configured to be able to change the set target pixel value 58. This allows the target pixel value 58 to be changed depending on the imaging region of the subject, the subject's body thickness, the purpose, etc., and therefore makes it possible to obtain an X-ray image with appropriate brightness depending on the subject's body thickness, the purpose, etc.

[0102] Second Embodiment Next, a second embodiment of the present invention will be described with reference to Figures 10 and 11. Unlike the first embodiment in which the operation unit 3 includes a first operation unit 3a and a second operation unit 3b, an X-ray fluoroscopic imaging apparatus 110 in the second embodiment is configured to allow selection between a first fluoroscopic mode and a second fluoroscopic mode. Components identical to those in the first embodiment are designated by the same reference numerals, and descriptions thereof will be omitted.

[0103] The operation unit 3 includes a foot switch 70 and an operation panel 33. The operation panel 33 is provided with a plurality of input units 33a (see FIG. 11B) that accept input operations related to X-ray irradiation. The input unit 33a includes an X-ray fluoroscopy button 36b and a target pixel value change button 37.

[0104] 11(a), the foot switch 70 is configured to receive input operations related to the start and end of X-ray irradiation by the X-ray irradiation unit 21. The foot switch 70 includes a fourth foot switch 74 used to perform fluoroscopic imaging based on the selected first or second fluoroscopic mode, and a fifth foot switch 75 used to perform general imaging.

[0105] 11(b), the X-ray fluoroscopy button 36b is configured to receive an input operation regarding the start and end of X-ray irradiation by the X-ray irradiator 21. The X-ray fluoroscopy button 36b is configured to receive an input operation regarding the start and end of fluoroscopic imaging based on the selected first fluoroscopy mode or second fluoroscopy mode.

[0106] The operation panel 33 is also provided with a first fluoroscopy mode selection button 38 and a second fluoroscopy mode selection button 39. The first fluoroscopy mode selection button 38 is a button that accepts an input operation for selecting the first fluoroscopy mode. The second fluoroscopy mode selection button 39 is a button that accepts an input operation for selecting the second fluoroscopy mode.

[0107] (First fluoroscopy mode and second fluoroscopy mode) The first fluoroscopy mode is a mode in which, when the pixel values ​​of the X-ray image generated by the image processing unit 61 are within the range of the target pixel value 58, the imaging control unit 60 stops the X-ray irradiation by the X-ray irradiation unit 21 and the image processing unit 61 stops generating the X-ray image, even if the operation unit 3 continues to accept input operations to irradiate X-rays.

[0108] The second fluoroscopy mode is a mode in which the imaging control unit 60 does not stop the X-ray irradiation unit 21 from emitting X-rays, and the image processing unit 61 generates an X-ray image, even if the pixel values ​​of the X-ray image generated by the image processing unit 61 are within the range of the target pixel value 58.

[0109] X-ray fluoroscopy in the first fluoroscopy mode differs from X-ray fluoroscopy in the first embodiment when an input operation is accepted by the first operation unit 3 a in that the first fluoroscopy mode is configured to be selected in advance by the first fluoroscopy mode selection button 38. In other words, X-ray fluoroscopy in the first fluoroscopy mode is performed in the same manner as X-ray fluoroscopy in the first embodiment when an input operation is accepted by the first operation unit 3 a, except that the first fluoroscopy mode selection button 38 is used and the first operation unit 3 a is not used.

[0110] Furthermore, X-ray fluoroscopy in the second fluoroscopy mode differs from X-ray fluoroscopy in the first embodiment when an input operation is accepted by the second operation unit 3 b in that the second fluoroscopy mode is configured to be selected in advance by the second fluoroscopy mode selection button 39. In other words, X-ray fluoroscopy in the second fluoroscopy mode is performed in the same manner as X-ray fluoroscopy in the first embodiment when an input operation is accepted by the second operation unit 3 b, except that the second fluoroscopy mode selection button 39 is used and the second operation unit 3 b is not used.

[0111] (X-ray image pixel value adjustment processing and X-ray image display processing) The X-ray image pixel value adjustment processing and X-ray image display processing by the control unit 6 according to the second embodiment will be described with reference to Figures 12 and 13. The X-ray image pixel value adjustment processing and X-ray image display processing by the control unit 6 are started based on the acceptance of an input operation to either the first fluoroscopy mode selection button 38 or the second fluoroscopy mode selection button 39. In the description of the X-ray image pixel value adjustment processing and X-ray image display processing by the control unit 6 according to the second embodiment described below, the "operation unit 3" refers to the fourth foot switch 74 or the X-ray fluoroscopy button 36b.

[0112] Furthermore, in the processing of steps S203 to S211, the acceptance of input operations to the operation unit 3 continues. If the acceptance of input operations to the operation unit 3 is canceled in the processing of steps S203 to S211, the processing ends. Furthermore, in the processing of steps S213 to S218 and step S221, the acceptance of input operations to the operation unit 3 continues. If the acceptance of input operations to the operation unit 3 is canceled in the processing of steps S213 to S218 and step S221, the processing ends. Note that the order of the processing steps can be reversed or executed simultaneously as long as there are no contradictions between them.

[0113] In step S201, the imaging control unit 60 determines whether an input operation has been accepted for the first fluoroscopy mode selection button 38 or the second fluoroscopy mode selection button 39. If an input operation for the first fluoroscopy mode selection button 38 has been accepted (Yes in step S201), the process proceeds to step S202. If an input operation for the second fluoroscopy mode selection button 39 has been accepted (No in step S201), the process proceeds to step S212 in FIG.

[0114] In step S202, the imaging control unit 60 determines whether or not an input operation related to X-ray irradiation has been accepted by the operation unit 3. If an input operation related to X-ray irradiation has been accepted by the operation unit 3 (Yes in step S202), the process proceeds to step S203. If an input operation related to X-ray irradiation has not been accepted by the operation unit 3 (No in step S202), the process proceeds to step S202.

[0115] The processing in steps S203 to S211 is the same as the processing in steps S102 to S110 in the first embodiment shown in FIG. 8, and therefore a description thereof will be omitted.

[0116] In step S212, the imaging control unit 60 determines whether or not an input operation related to X-ray irradiation has been accepted by the operation unit 3. If an input operation related to X-ray irradiation has been accepted by the operation unit 3 (Yes in step S212), the process proceeds to step S213. If an input operation related to X-ray irradiation has not been accepted by the operation unit 3 (No in step S212), the process proceeds to step S212.

[0117] The processing of steps S213 to S221 is the same as the processing of steps S111 to S119 in the first embodiment shown in Figure 9, except that the operation unit 3 is used instead of the second operation unit 3b, so the explanation will be omitted.

[0118] The other configurations of the second embodiment are similar to those of the first embodiment.

[0119] (Effects of Second Embodiment) In the second embodiment, the following effects can be obtained.

[0120] As described above, in the second embodiment, the first fluoroscopy mode and the second fluoroscopy mode are selectable. The imaging control unit 60 is configured to stop X-ray irradiation by the X-ray irradiator 21 and stop generation of an X-ray image when the first fluoroscopy mode is selected and the pixel value of the generated X-ray image falls within the range of the target pixel value 58, even if the operation unit 3 continues to accept an input operation for X-ray irradiation. Furthermore, when the second fluoroscopy mode is selected and the pixel value of the generated X-ray image falls within the range of the target pixel value 58, the imaging control unit 60 does not stop X-ray irradiation by the X-ray irradiator 21 and continues to generate an X-ray image. This allows the user to appropriately select, depending on the purpose, between the first fluoroscopy mode, in which X-ray irradiation by the X-ray irradiator 21 is stopped even if the operation unit 3 continues to accept an input operation for X-ray irradiation, and the second fluoroscopy mode, in which X-ray irradiation by the X-ray irradiator 21 is continued to accept an input operation for X-ray irradiation. This improves user convenience (usability).

[0121] The other effects of the second embodiment are the same as those of the first embodiment.

[0122] [Modifications] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the description of the above-mentioned embodiments, and further includes all modifications (modifications) within the meaning and scope of the claims.

[0123] For example, in the first and second embodiments, the X-ray fluoroscopy apparatus is a surgical X-ray fluoroscopy apparatus that includes an apparatus main body including an X-ray imaging unit and an arm, and a monitor cart, but the present invention is not limited to this. For example, the X-ray fluoroscopy apparatus may be an X-ray fluoroscopy apparatus that includes a close-up fluoroscopy table.

[0124] In the first and second embodiments, the operation unit includes a foot switch and an X-ray fluoroscopy button on the operation panel, but the present invention is not limited to this. For example, the operation unit may include a joystick, a cable switch, a keyboard, and a touch panel.

[0125] In the first and second embodiments, the target pixel value includes the average value, maximum value, and minimum value of the pixel values ​​of each pixel in a specific region set in each imaging region of the subject, and the imaging control unit is configured to stop X-ray irradiation by the X-ray irradiator when the average value, maximum value, and minimum value of the pixel values ​​of each pixel in the specific region included in the generated X-ray image are within the range of the target pixel value, even if the operation unit continues to accept an input operation to irradiate X-rays. However, the present invention is not limited to this. For example, the target pixel value may be configured to include at least one of the average value, maximum value, and minimum value of the pixel values ​​of each pixel in the specific region set in each imaging region of the subject. In this case, the target pixel value may include at least one of the average value, maximum value, and minimum value of the pixel values ​​of each pixel in a specific region set in each of the imaging regions of the subject, and the imaging control unit may be configured to stop the irradiation of X-rays by the X-ray irradiation unit when at least one of the average value, maximum value, and minimum value of the pixel values ​​of each pixel in the specific region acquired by the image processing unit is included within the range of at least one of the corresponding average value, maximum value, and minimum value of the target pixel value.

[0126] In the first and second embodiments, the target pixel value includes the average value, maximum value, and minimum value of the pixel values ​​of each pixel in a specific region set in each imaging region of the subject, but the present invention is not limited to this. For example, the target pixel value may be configured to include another value such as a median instead of any of the average value, maximum value, and minimum value of the pixel values ​​of each pixel in a specific region set in each imaging region of the subject, or may be configured to include another value such as a median in addition to the average value, maximum value, and minimum value.

[0127] In the first and second embodiments, the range of target pixel values ​​is a specific range centered on a preset target pixel value, but the present invention is not limited to this. For example, the range of target pixel values ​​does not have to be centered on the target pixel value as long as it is a specific range that includes the target pixel value.

[0128] In addition, in the first and second embodiments, examples have been shown in which the target pixel value is changeable, but the present invention is not limited to this. For example, the target pixel value may be configured to be unchangeable.

[0129] Furthermore, in the above-described first embodiment, an example was shown in which the operation unit included a second operation unit, but the present invention is not limited to this. For example, the operation unit may include only the first operation unit and not the second operation unit. Furthermore, in the above-described second embodiment, an example was shown in which the first fluoroscopy mode and the second fluoroscopy mode can be selected, but the present invention is not limited to this. For example, the operation unit may be configured to be able to execute only the first fluoroscopy mode.

[0130] In the first and second embodiments, the imaging control unit is configured to change the set X-ray irradiation conditions and irradiate X-rays when the pixel values ​​of the generated X-ray image are not within the range of target pixel values, but the present invention is not limited to this. For example, the imaging control unit may cause the X-ray irradiator to irradiate X-rays without changing the set X-ray irradiation conditions.

[0131] In the above first and second embodiments, the display control unit is configured to cause the display unit to display a message that enables the user to recognize that X-ray irradiation by the X-ray irradiator has been stopped, even if the first operation unit or the operation unit in the first fluoroscopy mode continues to accept an input operation to irradiate X-rays, based on the fact that the pixel values ​​in the X-ray image fall within a range of target pixel values. However, the present invention is not limited to this. For example, the display control unit may not cause the display unit to display a message that enables the user to recognize that X-ray irradiation by the X-ray irradiator has been stopped.

[0132] Aspects It will be appreciated by those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0133] (Item 1) An X-ray fluoroscopy apparatus comprising: an X-ray irradiator that irradiates X-rays; an X-ray detector that detects the X-rays irradiated by the X-ray irradiator; an operation unit that accepts an input operation related to the irradiation of X-rays by the X-ray irradiator; and a controller that controls the X-ray irradiator to irradiate X-rays based on the input operation on the operation unit and controls the generation of an X-ray image based on a detection signal output from the X-ray detector, wherein the controller is configured to stop the irradiation of X-rays by the X-ray irradiator when a pixel value of a pixel included in the generated X-ray image is within a range of a target pixel value even if the operation unit continues to accept the input operation to irradiate X-rays.

[0134] (Item 2) The X-ray fluoroscopy device according to Item 1, wherein the control unit is configured to change set X-ray irradiation conditions and cause the X-ray irradiator to irradiate X-rays in order to adjust pixel values ​​of pixels included in the X-ray image when the pixel values ​​of the generated X-ray image are not included in the range of the target pixel values, and to stop X-ray irradiation by the X-ray irradiator when the pixel values ​​of the X-ray image generated based on the changed X-ray irradiation conditions are included in the range of the target pixel values ​​even if the operation unit continues to accept an input operation to irradiate X-rays.

[0135] (Item 3) The X-ray fluoroscopy apparatus according to Item 1 or 2, further comprising a display unit that displays the X-ray image, wherein the control unit is configured to, based on the pixel value in the X-ray image falling within the range of the target pixel value and thereby causing the X-ray irradiation unit to stop emitting X-rays, cause the display unit to execute a display that allows the user to recognize that the X-ray irradiation by the X-ray irradiation unit has stopped, even if the operation unit continues to accept an input operation to irradiate X-rays.

[0136] (Item 4) The X-ray fluoroscopy apparatus according to Item 3, wherein the control unit is configured to cause the display unit to execute a recognizable display that the X-ray irradiation by the X-ray irradiation unit has stopped by causing the display unit to recognizably display that the last of the generated X-ray images at the time when the X-ray irradiation was stopped is displayed on the display unit as a recognizable display that the X-ray irradiation by the X-ray irradiation unit has stopped.

[0137] (Item 5) The X-ray fluoroscopy device according to any one of Items 1 to 4, wherein the control unit is configured to sequentially generate the X-ray images, and when the pixel values ​​in the set plurality of X-ray images are included in the range of the target pixel values, stop the X-ray irradiation by the X-ray irradiation unit even if the operation unit continues to accept an input operation to irradiate X-rays.

[0138] (Item 6) The X-ray fluoroscopy apparatus according to any one of Items 1 to 5, wherein the operation unit includes a first operation unit and a second operation unit, and the control unit is configured to: when an input operation to irradiate X-rays is accepted by the first operation unit, and when the pixel value of the generated X-ray image is included in the range of the target pixel value, stop the irradiation of X-rays by the X-ray irradiator and stop generation of the X-ray image even if the input operation to irradiate X-rays continues to be accepted by the first operation unit; and when an input operation to irradiate X-rays is accepted by the second operation unit, even if the pixel value of the generated X-ray image is included in the range of the target pixel value, not stop the irradiation of X-rays by the X-ray irradiator and generate the X-ray image.

[0139] (Item 7) An X-ray fluoroscopy apparatus according to any one of Items 1 to 5, configured to be able to select between a first fluoroscopy mode and a second fluoroscopy mode, wherein the control unit is configured to: when the first fluoroscopy mode is selected, if the pixel value of the generated X-ray image is within the range of the target pixel value, stop the irradiation of X-rays by the X-ray irradiator and stop the generation of the X-ray image even if the operation unit continues to accept an input operation to irradiate X-rays; and when the second fluoroscopy mode is selected, not stop the irradiation of X-rays by the X-ray irradiator and generate the X-ray image even if the pixel value of the generated X-ray image is within the range of the target pixel value.

[0140] (Item 8) The X-ray fluoroscopy apparatus according to Item 1, wherein the pixel values ​​include at least one of an average value, a maximum value, and a minimum value of pixel values ​​of each pixel in a specific region included in the X-ray image generated by the control unit, and the target pixel values ​​include at least one of an average value, a maximum value, and a minimum value of pixel values ​​of each pixel in the specific region set in each imaging region of the subject.

[0141] (Item 9) The X-ray fluoroscopic imaging apparatus according to Item 8, wherein the range of the target pixel value is a predetermined specific range centered around the target pixel value.

[0142] (Item 10) The X-ray fluoroscopic imaging apparatus according to Item 8, wherein the set target pixel value is changeable.

[0143] 3 Operation unit 3a First operation unit 3b Second operation unit 4a Display unit 21 X-ray irradiation unit 22 X-ray detection unit 54 X-ray irradiation conditions 58 Target pixel value 59 Specific region 6 Control unit 100, 110 X-ray fluoroscopic imaging device

Claims

1. An X-ray fluoroscopy device comprising: an X-ray irradiation unit that irradiates X-rays; an X-ray detection unit that detects the X-rays irradiated by the X-ray irradiation unit; an operation unit that accepts input operations related to the irradiation of X-rays by the X-ray irradiation unit; and a control unit that controls the irradiation of X-rays by the X-ray irradiation unit based on the input operation of the operation unit, and controls the generation of an X-ray image based on a detection signal output from the X-ray detection unit, wherein the control unit is configured to stop the irradiation of X-rays by the X-ray irradiation unit when a pixel value of a pixel included in the generated X-ray image is within a range of a target pixel value, even if the operation unit continues to accept the input operation to irradiate X-rays.

2. The X-ray fluoroscopy device of claim 1, wherein the control unit is configured to change set X-ray irradiation conditions and cause the X-ray irradiation unit to irradiate X-rays in order to adjust the pixel values ​​of pixels included in the X-ray image when the pixel values ​​of the generated X-ray image are not included within the range of the target pixel values, and to stop the irradiation of X-rays by the X-ray irradiation unit when the pixel values ​​of the X-ray image generated based on the changed X-ray irradiation conditions are included within the range of the target pixel values ​​even if the operation unit continues to accept an input operation to irradiate X-rays.

3. The X-ray fluoroscopy device of claim 1, further comprising a display unit for displaying the X-ray image, wherein the control unit is configured to, based on the pixel value in the X-ray image falling within the range of the target pixel value and thus causing the X-ray irradiation unit to stop emitting X-rays, cause the display unit to execute a display that enables the user to recognize that the X-ray irradiation unit has stopped emitting X-rays, even if the operation unit continues to accept an input operation to irradiate X-rays.

4. The X-ray fluoroscopy device according to claim 3, wherein the control unit is configured to cause the display unit to execute a recognizable display that the X-ray irradiation by the X-ray irradiation unit has stopped, by causing the display unit to display in a recognizable manner that the last of the generated X-ray images at the time when the X-ray irradiation was stopped is displayed on the display unit, as a recognizable display that the X-ray irradiation by the X-ray irradiation unit has stopped.

5. The X-ray fluoroscopy device of claim 1, wherein the control unit is configured to generate the X-ray images sequentially and, when the pixel values ​​in the set plurality of X-ray images are within the range of the target pixel value, to stop the emission of X-rays by the X-ray irradiation unit even if the input operation to irradiate X-rays continues to be accepted by the operation unit.

6. The X-ray fluoroscopy device according to claim 1, wherein the operation unit includes a first operation unit and a second operation unit; and the control unit is configured to: when an input operation for irradiating X-rays is accepted by the first operation unit, if the pixel value of the generated X-ray image is within the range of the target pixel value, stop the irradiation of X-rays by the X-ray irradiator and stop the generation of the X-ray image even if the input operation for irradiating X-rays continues to be accepted by the first operation unit; and when an input operation for irradiating X-rays is accepted by the second operation unit, even if the pixel value of the generated X-ray image is within the range of the target pixel value, not stop the irradiation of X-rays by the X-ray irradiator and generate the X-ray image.

7. An X-ray fluoroscopy device as described in claim 1, wherein the control unit is configured to be able to select between a first fluoroscopy mode and a second fluoroscopy mode, and the control unit is configured to: when the first fluoroscopy mode is selected, if the pixel value of the generated X-ray image is within the range of the target pixel value, stop the irradiation of X-rays by the X-ray irradiator and stop the generation of the X-ray image even if the operation unit continues to accept an input operation to irradiate X-rays; and when the second fluoroscopy mode is selected, even if the pixel value of the generated X-ray image is within the range of the target pixel value, not stop the irradiation of X-rays by the X-ray irradiator and generate the X-ray image.

8. The X-ray fluoroscopy device of claim 1, wherein the pixel value includes at least one of an average value, a maximum value, and a minimum value of the pixel values ​​of each pixel in a specific region included in the X-ray image generated by the control unit, and the target pixel value includes at least one of an average value, a maximum value, and a minimum value of the pixel values ​​of each pixel in the specific region set in each of the imaging regions of the subject.

9. The X-ray fluoroscopic imaging apparatus according to claim 8, wherein the range of the target pixel value is a specific range set in advance with the target pixel value at the center.

10. The X-ray fluoroscopic imaging apparatus according to claim 8, wherein the set target pixel value is changeable.

Images